CONICET | Buscador de Institutos y Recursos Humanos

We study the behavior of electrons interacting with a classical magnetic background via a strong Hund coupling. The magnetic background results from a Hamiltonian which favors at low temperature the emergence of a phase with nonzero scalar chirality. The strong Hund´s coupling combined with the total chirality of the classical spins induces in the electrons an effective flux which results in the realization of a band structure with nonzero Chern number. First, we consider as a magnetic background a classical spin system with spontaneous net chirality. We study the density of states and Hall conductance in order to analyze the topological transitions as a function of the Fermi energy and the temperature of the classical spins. We also study a similar model in which the Chern number of the filled bands can be "tuned" with the external magnetic field, resulting in a topological insulator in which the direction of the chiral edge mode can be reverted by reversing the orientation of the magnetic field applied to the classical magnetic system.